1. Field of the Invention
The fabric of the instant invention is intended for use in the papermaking industry and finds particular application in the wet press and dryer sections of papermaking equipment. In such equipment, the fabric is a carrying or conveying means which is intended for use in applications requiring either an endless or flat woven fabric. In the papermaking industry, fabrics of the instant invention are frequently referred to as felts, when used in the wet press or dryer section, since they generally comprise a carrier fabric or layer which runs in contact with the equipment and a felt surface which runs in contact with the paper.
2. Description of the Prior Art
It has been recognized in the prior art that it is desirable to provide a felt for use in papermaking machinery which comprises an under layer made of relatively rigid non-deformable material having a compressible felt layer thereon. It has been further recognized by the prior art that it is advantageous to use a needled felt layer in combination with the relatively rigid non-deformable under layer. One example of such a prior art fabric is found in U.S. Pat. No. Re. 21,890 entitled Industrial and Papermakers Felts. This prior art reference discloses the most commonly known needled papermakers felt utilized in the papermaking industry. More recently, an effort to improve the papermakers felt was disclosed in U.S. Pat. No. 4,500,588. This patent discloses the use of a barrier layer contained within the felt. The purpose of this barrier layer is to prevent filler material from penetrating from the surface of the felt into the remainder of the felt.
The difficulty with the prior art approach comes in applying the batt or felt surface to the under layer and in obtaining a batt of sufficient density in an economic manner without damaging the under layer fabric during the needling operation.